1. Field of the Invention
The present invention relates to a leaf management apparatus such as an automatic teller machine (ATM) located in a bank, a convenience store, and the like, for example. In particular, the invention relates to a leaf transfer mechanism unit, in general incorporated in the ATM, comprising a pickup roller, an urging member designed to move toward the pickup roller, and a drive source generating a driving force supplied to the urging member.
2. Description of the Prior Art
In general, a rotative pickup roller is employed in a leaf transfer mechanism unit to transfer bills received in a leaf reception room. The bills should be urged against the pickup roller. When the pickup roller is driven to rotate, the bills can sequentially be transferred one by one. An urging member is designed to move forward toward the pickup roller so as to urge the bills against the pickup roller. The forward movement of the urging member can be achieved by a driving force generated at a drive source such as a servo motor responsive to pulse signals, for example.
If an excessive urging force is applied to a stack of bills on the pickup roller in the leaf transfer mechanism unit, the bills cannot be transferred one by one. In other words, a plurality of bills are simultaneously transferred out of the leaf reception room. On the contrary, if an urging force applied to the bills on the pickup roller is too small, no bills can be transferred out of the leaf reception room. It is difficult to control an urging force applied to the bills on the pickup roller based on a driving force supplied from the aforementioned servo motor.
For example, Japanese Patent Laid-open Nos. 5-147193 and 6-100183 disclose proposals to utilize an elastic spring to transmit a driving force from the drive source to the urging member. The elastic force of the spring serves to optimize the urging force with a relatively simple structure. However, when the spring is interposed between the urging member and the drive source in this manner, a precise control of positioning the urging member can hardly be achieved, since the elastic spring may stretch and shrink in response to the magnitude of load applied to the spring.